From Anna Monette Roberts, POPSUGAR Food
In a mason jar, combine the milk, chocolate, vanilla extract, and butter flavor.
Microwave for about 1 minute and 10 seconds, or until small bubbles form at the top of the milk and the chocolate appears slightly melty.
Carefully remove (you may need to do so with a towel or oven mitt). Secure the lid on the mason jar, and shake until the chocolate dissolves into the milk and becomes frothy.
Unscrew the cap, transfer to a mug, and top with whipped cream and sprinkles.